Phakic IOLs indicated for at-risk moderate or high myopes

Phakic IOL implantation can be an alternative to LASIK and PRK in some eyes with moderate to high myopia, a surgeon said.

Jason E. Stahl, MD, offered pearls on patient selection and indications during Refractive Subspecialty Day preceding the joint meeting of the American Academy of Ophthalmology and the Middle East Africa Council of Ophthalmology in Chicago.

“Phakic intraocular lenses can offer predictability and stability, an advantage over LASIK,” Dr. Stahl said. “In my practice, the phakic IOLs are certainly an attractive method compared to LASIK and PRK for the treatment of high myopia and also moderate myopia if indicated based on the patient evaluation.”

Surgeons are increasingly comfortable performing LASIK or PRK with the latest excimer laser platforms, but some patients are not suited for laser refractive surgery, Dr. Stahl said.

“Some individuals, because of thin corneas or corneal irregularities, are not going to be candidates,” he said. “Thankfully, we do have phakic intraocular lens technology that is able to very nicely treat these patients, such as a patient I treated 5 years ago … who still has 20/15 uncorrected visual acuity today.”

Moderate, high myopia

Moderate myopia is defined as refractive error of –3 D to –6 D. High myopia is error greater than –6 D.

Patients with 6 D to 8 D of myopia are normally excellent candidates for wavefront-guided or wavefront-optimized laser ablation. Patients with 8 D or higher myopia are prime candidates for implantation of a phakic IOL, Dr. Stahl said.

“We get very good vision right away on day 1,” he said.

Two phakic IOLs have been approved by the U.S. Food and Drug Administration: the Verisyse (Abbott Medical Optics) and the Visian Implantable Collamer Lens (ICL, STAAR Surgical). The Dutch firm Ophtec markets the Verisyse as the Artisan outside the United States.

The Verisyse lens is designed to correct 5 D to 20 D of myopia.

“We have studies that compared this lens with LASIK for high myopia, from –8 D to –12 D,” Dr. Stahl said. “The phakic lens is superior in its safety index. … There has also been an increase in the contrast sensitivity that has been shown with this technology.”

The Visian ICL has been shown to be safer and more predictable than LASIK in treating myopia up to 12 D, Dr. Stahl said.

Safety, predictability and stability

Three-year data on phakic IOL outcomes showed superior predictability and long-term stability compared with 3-month data on post-LASIK outcomes, Dr. Stahl said.

“There is no change in the stability, whether we’re talking about the Artisan lens or whether we’re talking about the Visian lens,” he said.

Phakic IOL implantation poses some risk, Dr. Stahl said.

“There are safety concerns,” he said. “This is intraocular surgery, so we have to watch the long-term endothelial cell count. We need to monitor these patients … and, lastly, tell phakic IOL patients that they cannot rub their eyes. There are concerns that placing these in younger patients that you need to have long-term follow-up. In addition, cataract formation is also something that can develop in patients who had phakic IOLs.”

Laser refractive surgery for moderate to high myopia is also associated with various risks, such as higher-order aberrations that decrease visual quality, postoperative ectasia and keratoconus, Dr. Stahl said. – by Matt Hasson

• Jason E. Stahl, MD, can be reached at Durrie Vision, 5520 College Blvd., Suite 201, Overland Park, KS, 66211; 913-491-3330; fax: 913-491-9650; e-mail: jstahl@durrievision.com.
• Disclosure: Dr. Stahl is a consultant for Alcon, Abbott Medical Optics, Bausch + Lomb and TrueVision.